Valve Analytical System

ABSTRACT

A lab on a valve analytical system includes a rotary sample preparation assembly having a stator and a rotor. The rotor includes a plurality of integral syringe pumps which can be aligned with passages formed within the stator. The stator passages can be connected with fluid inlet connector which connect the sample preparation assembly with fluid sources, and fluid outlet connectors which connect the sample preparation assembly with one or more wet chemical analytical devices. Some embodiments can include a mixer and optical sensor connected with the fluid outlets. One or more drive motors can be used to control simultaneous actuation of one or more of the syringe pumps, thereby providing for simultaneous delivery of metered volumes of fluid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority to and is a divisionalapplication of U.S. application Ser. No. 12/565,520, filed on Sep. 23,2009, of which the entire contents are hereby incorporated by reference.

FIELD

This disclosure generally relates to an analytical system for performingautomated wet chemical analysis. In particular, this disclosure relatesto a valve analytical system for determining the concentration of aperacid and peroxide within a use composition.

BACKGROUND

An analytical procedure in chemistry consists of a series of operationscarried out in fixed sequence which may be considered steps or stages.One step in chemical analytical procedure often involves the delivery ofpredetermined volumes of one or more fluid chemicals. When performed byhand, analytical chemistry procedures can produce varied results due toa number of factors such as, for example, the usage of an improper orinaccurate volume of a fluid chemical. Moreover, manual analyticalchemistry procedures can be tedious and time consuming. Accordingly,there is a desire to automate analytical chemistry procedures.

One application of analytical chemistry is to determine theconcentration of one or more analytes within a composition. For example,the analytical chemical procedures can be useful in the analysis andmonitoring of antimicrobial compositions. Antimicrobial compositions areused in a variety of automated processing and cleaning applications toreduce microbial or viral populations on hard or soft surfaces or in abody or stream of water. For example, antimicrobial compositions areused in various applications including kitchens, bathrooms, factories,hospitals and dental offices. Antimicrobial compositions are also usefulin the cleaning or sanitizing of containers, processing facilities orequipment in the food service or food processing industries, such ascold or hot aseptic packaging. Antimicrobial compositions are also usedin many other applications including but not limited to clean-in-placesystems (CIP), clean-out-of-place systems (COP), washer-decontaminators,sterilizers, textile laundry machines, filtration systems, etc.

Whatever the application, an antimicrobial or “use” composition is acomposition containing a defined minimum concentration of one or moreactive components which exhibit desired antimicrobial properties. Onesuch category of active antimicrobial component are peracids, such asperoxycarboxylic acid (peracid), peroxyacid, peroxyacetic acid,peracetic acid, peroctanoic acid, peroxyoctanoic acid and others.

The concentration of active components in the use composition is chosento achieve the requisite level of antimicrobial activity. In usecompositions in which one or more peracids are the active component, andin the instance of a recirculating process, the concentration ofhydrogen peroxide tends to increase over time while the concentration ofperacid decreases. However, in order to maintain the requisite level ofantimicrobial activity, the amount of peracid in the use compositionmust be maintained at a defined minimum concentration. In addition, asthe amount of hydrogen peroxide in the use composition increases, theuse composition may exceed a defined maximum concentration of hydrogenperoxide in the solution. In some applications, for example bottlingline cleansing, the allowable amount of residual hydrogen peroxide issubject to government regulations. Once the hydrogen peroxideconcentration exceeds the maximum concentration, the spent usecomposition is discarded and a new use composition generated.

To ensure that the amount of peracid is maintained at or above someminimum concentration and to determine when the amount of hydrogenperoxide reaches or exceeds a maximum concentration, it is necessary todetermine the concentration of peracid(s) and hydrogen peroxide in theuse composition. In the past, to determine both the peracidconcentration and the hydrogen peroxide concentration in a usecomposition has required multiple time consuming manual titrations,several different reagents and relatively large volumes of usecomposition. Moreover, past devices and methods for determining bothperacid and hydrogen peroxide concentrations were effective over only anarrow range of concentrations.

SUMMARY

Certain embodiments disclosed herein provide a rotary valve analyticalsystem including a rotor, a stator, syringe and rotor drive motors, amixer, and an optical sensor. The rotor is rotatable about an axisperpendicular to a face of the rotor and includes a plurality of syringebarrels formed therewithin. The syringe barrels extend into the rotorfrom openings within the rotor face and are disposed at selected radialdistances from the axis. The stator is coaxially positioned relative tothe rotor and includes a stator face which opposes and is in sealable,slidable contact with the rotor face. The stator includes a plurality ofsets or groups of openings each of which includes a plurality ofopenings disposed at a common radial distance from the axis which extendthrough the stator forming passages to an outlet port. The common radialdistance of each group of openings is equal to one or more of theselected radial distances of the openings in the rotor face. The syringedrive motor is mechanically coupled with a plurality of plungers and isadapted to drive and withdraw one plunger within each syringe barrelwithin the rotor. The rotor drive motor is mechanically coupled with therotor and adapted to cause the rotor to rotate relative to the stator. Aplurality of inlet and outlet tubes can be coupled with the outlet portsof the stator to deliver fluid to the system, or deliver dispensed fluidfrom the system to a device. In some embodiments, the rotary valveanalytical system includes a fluid mixer, for mixing delivered fluid anda sensor in fluid communication with the mixer and adapted to perform ameasurement on the mixed fluids.

In another aspect, embodiments of the invention include a method foranalyzing one or more characteristics of a use composition. The methodincludes providing a rotary valve analytical system such as, forexample, that described above. The method further includes rotating therotor to a first position, such that the syringe barrels within therotor are aligned with one or more of the inlet passages within thestator. Additionally in this position, the other openings within thestator face are sealed by the rotor face. One or more of the alignedinlet passages are in fluid communication with the source of the usecomposition. The method further includes simultaneously drawing fluidinto each of the syringe barrels from the aligned inlet passages. Then,the rotor can be rotated to a second position, such that each of thesyringe barrels are aligned with one of the outlet passages and theother openings within the stator face are sealed by the rotor face. Thefluid within the syringe barrels can then be simultaneously driventhrough the aligned fluid outlet passages and into outlet lines. In someembodiments, the method further includes mixing the dispensed fluids inthe mixer resulting in a sample mixture within the outlet line. Then,one or more properties of the sample mixture can be measured with thesensor. The measured properties may be indicative one or morecharacteristics of the use composition, which can then be determinedbased on the measurement.

In another aspect, the invention includes a lab on a valve analyticalsystem for determining a concentration of a peracid and a peroxidewithin a use composition. The lab on a valve assembly includes a valveassembly, a mixer, and a sensor. The valve assembly includes a rotor, astator and a plurality of syringe plungers. The rotor has a rotor faceand a plurality of syringe barrels extending into the rotor fromopenings in the rotor face. The rotor is rotatable about an axisperpendicular to the rotor face. The stator is disposed coaxially withthe rotor and includes a stator face in sealable, slidable, rotarycontact with the rotor face. The stator further includes a plurality ofgroups of passages, each group of passages including a plurality ofpassages which extend through the stator from an opening on the statorface to a connector port. Each passage of the groups of passages isdisposed at a common radial distance from the axis such that each groupof passages can be aligned with at least one syringe barrel of the rotorby rotating the rotor relative to the stator. One of the syringeplungers is disposed within each of the syringe barrels, such that eachsyringe plunger can draw fluid into and drive fluid from the syringebarrel in which it is disposed. In addition, one or more of theconnector ports is in fluid communication with a source of the usecomposition, one or more of the connector ports is in fluidcommunication with a source of a reagent, and one or more of theconnector ports is in fluid communication with a source of an acid. Themixer is in fluid communication with the connector port of one of thepassages of each group of passages of the stator. The mixer is adaptedto produce a sample mixture comprising quantities of the usecomposition, the reagent, and the acid. And, the sensor is in fluidcommunication with the mixer. The sensor is adapted to measure one ormore properties of the sample mixture indicative of the concentration ofthe peracid and the concentration of the peroxide within the usecomposition.

These and various other features and advantages will be apparent from areading of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative of particular embodiments of theinvention and therefore do not limit the scope of the invention. Thedrawings are not to scale (unless so stated) and are intended for use inconjunction with the explanations in the following detailed description.Embodiments of the invention will hereinafter be described inconjunction with the appended drawings, wherein like numerals denotelike elements.

FIG. 1 is a schematic view of a lab on a valve analytical systemaccording to some embodiments.

FIG. 2A is a top plan view of a sample preparation assembly according tosome embodiments.

FIG. 2B is a cross-sectional view of the sample preparation assembly ofFIG. 2A from the perspective of lines B-B.

FIG. 2C is a plan view of a rotor of the sample preparation assembly ofFIG. 2B from the perspective of lines C-C.

FIG. 3A is a top plan view of a sample preparation assembly according tosome embodiments.

FIG. 3B is a plan view of a rotor of the sample preparation assembly ofFIG. 3A.

FIG. 4A is a front view of a portable analyzer according to someembodiments.

FIG. 4B is a rear view of the portable analyzer of FIG. 4A.

FIG. 4C is a cross-section view of the analyzer of FIG. 4B from theperspective of lines C-C.

FIG. 5A is a cross-sectional view of the lab on a valve assemblyindicated by region 5A of FIG. 4C.

FIG. 5B shows a cross-sectional view of the lab on a valve assembly ofFIG. 5A along the plane B-B.

FIGS. 6A-6C show an exploded view of the lab on a valve assembly ofFIGS. 5A and 5B.

FIG. 7A shows a transparent, perspective view of the disks whichcomprise a lab on a valve assembly according to some embodiments.

FIG. 7B shows top and bottom views of the interface disk shown in FIG.7A.

FIG. 7C shows top and bottom views of the valve disk shown in FIG. 7A.

FIG. 7D shows top and bottom views of the rotor disk shown in FIG. 7A.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 shows a schematic view of a lab on a valve analytical system 100according to some embodiments. The lab on a valve analytical system 100comprises a sample preparation assembly 110 in fluid connection withsources of fluid inputs 112, 114, 116. The sample preparation assembly110 manages the simultaneous dispensing of predetermined volumes ofselected ones of the connected fluids. The metered fluids are dispensedvia fluid outlets 118 connected with the sample preparation assembly110. A mixer 120 connected with the fluid outlets 118 mixes thedispensed fluids, providing a sample mixture. The sample mixture isdelivered to a sensor 122, which can obtain response data indicative ofcharacteristics of the sample mixture. Once the fluid has passed throughsensor 122, it can be disposed of via connection to waste 124. Operationof the sample preparation assembly 110 and sensor 122 can be controlledby a controller 126. In addition, the controller can process theresponse data to determine properties of one or more of the fluids.

Lab on a valve analytical systems, according to some embodiments, enablethe automation of manual wet chemical analytical procedures. Forexample, the lab on a valve system 100 can be configured as a usecomposition monitor. A use composition monitor may be connected to asource of use composition 114, to monitor characteristics of the usecomposition such as, for example, the presence or concentration ofselected analytes. In particular, some embodiments are well suited foruse as a use composition monitor for determining the concentration ofperacid and/or hydrogen peroxide in a use composition. For example, theuse composition may be monitored to ensure that the concentration ofperacid satisfies at least a minimum threshold concentration. The usecomposition may also be monitored to determine when the concentration ofhydrogen peroxide exceeds a maximum threshold concentration. Of course,embodiments of the lab on a valve analytical systems disclosed hereinshould not be limited to monitoring devices, for example, such systemscan be used as analytical instruments or for other purposes.

In some embodiments, the lab on a valve analytical system 100 can beadapted to perform a kinetic assay procedure for determining theconcentrations of peracid and/or hydrogen peroxide in the usecomposition. This is accomplished by exploiting the difference inreaction rates between peracid and hydrogen peroxide when using, forexample, a buffered iodide reagent to differentiate peracid and hydrogenperoxide concentrations when both these analyte compounds are present inthe use composition. In such use the inputs of the sample preparationassembly 110 can be coupled with a source of reagent 112 a, a source ofan acid 112 b, and a source of the use composition 114. In addition,some embodiments can include a connection to a source of water 116. Theuse composition monitor may also determine the concentrations of peracidand/or hydrogen peroxide in the presence of other additionalingredients, such as acidulants, one or more stabilizing agents,nonionic surfactants, semi-polar nonionic surfactants, anionicsurfactants, amphoteric or ampholytic surfactants, adjuvants, solvents,additional antimicrobial agents or other ingredients which may bepresent in the use composition.

In a use composition including hydrogen peroxide and a peracid such asperoxyacetic acid, a buffered iodide changes color as it is oxidized byboth the peroxyacetic acid and the hydrogen peroxide to form triiodideion. However, as the peroxyacetic acid and the hydrogen peroxide in theuse composition compete for the available iodide ions, reaction with theperoxyacetic acid proceeds at a faster rate than the reaction with thehydrogen peroxide, as shown in the following equations:

2CH₃COOOH+(excess)I⁻→I₃ ⁻+2CH₃COOH FASTER

H₂O₂+(excess)I⁻+2H⁺→I₃ ⁻+2H₂O SLOWER

This difference in reaction rates may be exploited to differentiateperacid and hydrogen peroxide concentrations when both these analytecompounds are present in the use composition. For example, an opticalsensor 122 can measure colorimetric data as a function of time of asample within the sensor 122. This data can include, for example,absorbance data of a sample mixture undergoing the above reactions.Because the triiodide product of the above reactions manifests as achange in absorbance, the measured colorimetric data can be used todetermine the concentrations of peracid and peroxide within the usecomposition. In particular, the initial absorbance, A₀, is dependent onthe peracid concentration and independent of the peroxide concentration;and the rate of change in absorbance, A_(t), is dependent on theconcentration of peroxide and independent of the peracid concentration.Accordingly, measurements of the initial absorbance A₀ and the rate ofchange of absorbance A_(t) can be utilized to determine values ofperacid and peroxide concentration within a use composition. Thiscalculation is described in more detail in commonly owned U.S. patentapplication Ser. No. 12/370,369, entitled, “Wide Range KineticDetermination of Peracid and/or Peroxide Concentrations,” which ishereby incorporated by reference.

The concentrations of peracid and/or peroxide determined by the lab on avalve use composition monitor 100 may be used, for example, as feedbackto another system to maintain the peracid concentration in the usecomposition within a predefined range. If, for example, theconcentration of peracid in the use composition decreases below apredetermined level, the use composition may be replenished by adding aconcentrated peracid composition to the use composition. As anotherexample, if the concentration of peroxide in the use composition exceedsa predetermined level, the use composition may be replenished byemptying the use composition vessel of the spent use composition andgenerating a new use composition.

FIG. 2A shows a top plan view of a lab on a valve analytical system 200according to some embodiments. The lab on a valve analytical system 200comprises a rotary valve analytical system comprising a samplepreparation assembly 210 having a plurality of fluid inputs and fluidoutputs. The fluid outputs of the sample preparation assembly areconnected with a mixer 120 which is connected with a sensor 122 and awaste line 124. As above, the system 200 can be controlled by acontroller 126. The sample preparation assembly 210 provides for thesynchronous delivery of a plurality of fluids to the mixer 120 andsensor 122. Thus, sample preparation can be processed in parallel,rather than the serial preparation of sample mixtures characteristic ofsequential injection analysis systems. Parallel processing of samplemixtures can afford significant reductions in sample preparation time,thus decreasing the time required to perform a measurement cycle.Accordingly, embodiments according to the present invention can providefor more frequent use composition analysis. For example, in someembodiments, analytical systems adapted to determine the concentrationsof peracid and peroxide within a use composition can perform ameasurement in approximately 5 seconds.

The sample preparation assembly 210 will be described with reference toFIGS. 2A, 2B, and 2C. FIG. 2A shows a top plan view of a samplepreparation assembly 210 according to some embodiments. FIG. 2B shows across-sectional view of the sample preparation assembly 210 of FIG. 2Afrom the perspective of lines B-B. FIG. 2C shows a plan view of a rotor211 of the sample preparation assembly of FIG. 2B from the perspectiveof lines C-C.

With reference to FIG. 2B, the sample preparation assembly 210 comprisesa rotor 211 rotatably mounted to a stator 212. The rotor 211 and stator212 are coupled by a bolt 213 which defines an axis of rotation 214about which the rotor 211 is rotatable. The bolt 213 provides acompression force, holding a face of the rotor 211 in sealable, slidablecontact with a face of the stator 212 at an interface 215. The rotorstator face and rotor face interact such that the rotor face can slideover the stator face as the rotor 211 rotates about the axis 214 whilemaintaining a fluid seal such that fluid cannot seep between the twofaces at the interface 215.

The stator 212 further comprises a plurality passages 217 passingtherethrough. The passages 217 extend through the stator from openings218 at the stator face to outlet ports 219. The outlet ports 219 can beconnected with fluid inlet connectors 220 or outlet connectors 221 asshown in FIG. 2A. The passages 217 within the stator 212 are arrangedinto groups of passages 222. Any reference made herein to a passage by asingle part number shall be construed as referring to all passageswithin the sample preparation assembly. Individual passages will bereferred to by the group and passage number of the passage to which itconnects. For example, passage 217-1,1 is the first passage of the firstgroup of passages 222-1. Likewise, passage 217-3,2 is the second passageof the third group of passages 222-3. In addition, any reference hereinto inlet connectors and/or outlet connectors by a single part numbershall be construed as referring to all inlet connectors or outletconnectors coupled with the sample preparation assembly. References toindividual inlet connectors or individual outlet connectors will be madeby including the group and passage number to which the connectorconnects. For example, inlet connector 220-1,1 is the inlet connectorconnected to passage 217-1,1 and outlet connector 221-3,2 is the outletconnector connected to passage 217-3,2.

For example, the embodiment of FIG. 2A shows a stator 212 having fourgroups of passages 222. Each group of passages 222 comprises threepassages. Each of the passages of a selected group of passages isdisposed at a common radial distance from the axis 214. For example,each of the passages of group 222-1 of the embodiment of FIG. 2A aredisposed a radial distance D_(g) from the axis 214. Moreover, in someembodiments, common angular distances separate the passages within eachof the groups of passages. For example, the angular distance separatingpassage 217-1,1 and passage 217-1,2 is equivalent to the angulardistance separating (i) passages 217-2,1 and 217-2,2, (ii) passages217-3,1 and 217-3,2, and (iii) passages 217-4,1 and 217-4,2.

Referring to FIG. 2B, the sample preparation assembly 210 furthercomprises a rotor 211. The rotor 211 is rotatable relative to the stator212. The rotor 211 includes a plurality of syringe barrels 225 formedtherein. Each syringe barrel 225 extends into the rotor 211 from anopening on the rotor face. The syringe barrels 225 are disposed withinthe rotor at selected radial distances D_(s) from the axis 214 such thatone syringe barrel is associated with each of the groups of passages 222within the stator 212. That is, the selected radial distance D_(s) of atleast one syringe barrel 225 is equal to the common radial distanceD_(g) for each group of passages. Accordingly, when the rotor 211 isrotated such that an opening on the rotor face aligns with an opening onthe stator face, the passage 217 connects the syringe barrel 225 withthe connected inlet or outlet connector.

FIG. 2C shows a top plan view of a rotor 211 according to someembodiments. From this view, the rotor face and plurality of openings,which form syringe barrels 225 therein, are visible. This embodimentincludes four syringe barrels 225. Each syringe barrel is positionedrelative to the axis such that it corresponds with a single group ofpassages 222 within the stator. For example, syringe barrel 225-1 ispositioned at a selected radial distance D_(s) that is equivalent toradial distance D_(g) of group 222-1, such that syringe barrel 225-1 isassociated with group 222-1 of FIG. 2A. Moreover, the additional syringebarrels of the rotor are positioned relative to syringe barrel 225-1such that alignment of syringe barrel 225-1 with a passage of group222-1, will cause each of the other syringe barrels within the rotor toalign with the corresponding passage of a different group of passages.For example, in FIG. 2C, the rotor is shown rotated such that syringebarrel 225-1 is in position 2. In this position, the syringe barrel225-1 is aligned with passage 217-1,2 of the stator (i.e. a connectionis made between the syringe barrel 225-1 and outlet connector 221-1). Inaddition, this rotor position 2 further aligns (i) syringe barrel 225-2with passage 217-2,2, (ii) syringe barrel 225-3 with passage 217-3,2,and (iii) syringe barrel 225-4 with passage 217-4,2.

In operation, rotor 211 can be rotated to change the alignment ofsyringe barrels and passages. In embodiments where the passages 217 ineach group of passages 222 are separated by common angular distances,rotation of the rotor can be used to select which of the passages 217are connected with the syringe barrels 225. For example, rotation of therotor 211 of FIG. 2C by an angle θ_(A), i.e. to position 1, will resultin aligning syringe barrel 225-1 with passage 217-1,1 of the stator 212.Likewise, syringe barrel 225-2 will be aligned with passage 217-2,1,syringe barrel 225-3 will be aligned with passage 217-3,1, and syringebarrel 225-4 will be aligned with passage 217-4,1. Similarly, rotationof the rotor 211 by an angle θ_(B) transitions the rotor to position 3,thus aligning each of the syringe barrels 225 with the third passage217-x,3 of each group of passages 222-x.

Rotation of the rotor 211 can be accomplished, for example, by theactuation of a rotor drive motor 230. The rotor drive motor 230 can becoupled with the stator 212 and adapted to drive a rotor drive gear 231.Rotor teeth 232 disposed along the perimeter of rotor 211 can engagerotor drive gear 231 such that as rotor drive gear 231 is driven, rotor211 rotates about axis 214. One of ordinary skill will appreciate otherways to drive rotor 211, all of which should be considered within thescope of invention.

Each syringe barrel 255 is adapted to receive a plunger 226. Eachplunger 226 comprises a drive shaft and a plunger head. The plunger headis disposed within the syringe barrel 225 so as to form a fluid-tightseal with the walls of the syringe barrel 225. This seal may befacilitated, for example, by the inclusion of a rubber o-ring positionedabout the perimeter of the plunger head. The plunger drive shaft iscoupled with the plunger head and adapted to position the plunger headwithin the syringe barrel 225. For example, in some embodiments, theplunger drive shaft comprises a threaded shaft threadably engaged with asyringe gear 233 at the end opposite the plunger head. Rotation of thesyringe gear 233 causes the shaft (and thus the plunger head) totranslationally shift within the syringe barrel 225. Moreover, theplunger can include a means for preventing rotation of the plunger driveshafts. This can be, for example, a pin through the plunger drive shaftwhich is received within a corresponding slit in the body of the rotor211. Such an arrangement allows the shaft and pin to movetranslationally during rotation of the syringe gear 233. Another way toeliminate the possibility of rotation plunger is to offset the plungerdrive shaft from the center of the plunger head. Alternatively, in someembodiment the plunger heads and syringe barrels can be oval in shape toprevent rotation of the plunger head. Accordingly, the syringe barrels225 and plungers 226 act as syringe pumps, where fluid can be drawn intothe syringe barrel via the opening in the rotor face by withdrawing theplunger head and fluid can be delivered from the syringe barrel via theopening the rotor face by driving the plunger into the syringe barrel.

In some embodiments, two or more of the syringe pumps can besimultaneously controlled. For example, a syringe drive gear 234 drivenby a syringe drive motor 235 can contact each of the syringe gears 233.Activation of the syringe drive motor 235 can drive the syringe drivegear 234, which in turn drives each of the connected syringe gears 233.In some embodiments, the syringe drive motor 235 can be coupled with ahousing 236 that encloses the rotor so as to protect the mechanicalcomponents from physical interruption. Of course, other syringe pumpdrive schemes can be applied, for example, each syringe pump can includeits own drive motor such that each of the plungers are separatelycontrollable. Moreover, the threadable connection to each drive shaftcan be selected such that a single drive motor can be used to drivemultiple plungers for different distances. Each of these and othervariations that are within the capabilities of one of ordinary skill inthe art should be considered within the scope of invention.

Thus, the rotor is provided with a plurality of pumps. Each of the pumpsis embedded within the rotor such that an opening in the rotor faceprovides the inlet to the pump. The pumps are configured to selectivelydraw in fluid from an aligned passage, hold the fluid, and drive thefluid out of the pump to an aligned passage. In many embodiments, therotor is rotated as fluid is held within the pump, thus the passage towhich fluid is driven is not the same passage from which the fluid wasdrawn. Thus, the pumps, combined with the rotation of the rotor, caneffectuate delivery of fluid from an inlet passage to an outlet passage.While the embodiments described herein have referenced syringe pumps,generally any micropump capable of accomplishing the above describedfunction can be utilized. For example membrane micropump with thermal,electrostatic, or piezoelectric actuation can be used.

Thus, embodiments of the sample preparation assembly 210, can providefor simultaneous delivery of multiple fluids to one or more fluidoutlets 221. For example, the rotor 211 can be rotated to position 1,such that the syringe barrels 225 of the rotor are aligned with thefirst stator passages 217-x,1. At this position, the syringe barrels arein fluid communication with the first passages, and thereby the fluidsources connected to the first passages 217-x,1 via inlet connectors220-x,1. The other openings within the stator face abut the rotor faceand are thereby sealed shut. Fluid can be drawn into each of the syringebarrels by simultaneously activating the syringe pumps, for example, bydrawing the plungers 226 within the syringe barrels 225.

Once a desired volume of fluid has been drawn into the syringe barrel225, the rotor can be rotated to second position 2. At position 2, eachof the syringe barrels 225 are aligned with one of the passages 217-x,2connected with an outlet connector 221. During rotation, fluid remainssealed within the syringe barrel by the sealed connection of the openingwithin the rotor with the stator face. Moreover, the additional passageswithin the stator are sealed by the opposing rotor face, thus preventingleakage of fluid from passages connected with inlet connectors 220. Uponreaching position 2, the fluid can be simultaneously driven from thesyringe barrel 225, for example, by simultaneously driving the plungers226 into the syringe barrels 225. Thus a plurality of fluids can besimultaneously delivered from the sample preparation assembly 210.

In some embodiments the fluid inlet connectors 220 comprise tubes.Likewise, the outlet connectors 221 can comprise tubes. Connections tothe sample preparation assembly can comprise generally any fluid-tightconnection. For example, the tubes can comprise standard 1 mm diametertubing connected to the sample preparation assembly via threaded ferruleconnection. Suitable tubing and connectors are available, for example,from Valco Instruments Co. Inc., of Houston, Tex. Alternatively, in someembodiments, the inlet and or outlet passages can comprise internalpassages formed within sample preparation assembly. One example is shownwith respect to FIGS. 5A-7D discussed below, where the passages areformed by sealed channels etched into a portion of an interface disk.

FIGS. 3A and 3B show views of an alternative embodiment of a samplepreparation assembly according to some embodiments. FIG. 3A is a topplan view of the sample preparation assembly 300. FIG. 3B is a plan viewof a rotor 311 of the sample preparation assembly 300 of FIG. 3A. Thisembodiment is similar to that shown in FIGS. 2A-2C, however here, eachgroup of passages 322 of the stator 312 is arranged at a distinct commonradial distance D_(g)-1, D_(g)-2, D_(g)-3 from the axis 314. Accordinglyeach inlet connector 320 and outlet connector 321 is radially alignedabout the stator 312 such that simultaneously actuated inlet connectors(i.e. inlet connectors 320-x,1 or inlet connectors 320-x,3) and outletconnectors 321-x,2. Likewise, with reference to FIG. 3B, the rotor 311includes a plurality (here three) of syringe barrels 325 formed therein.These syringe barrels 325 are aligned at radial distances from the axis314 such that one syringe barrel corresponds with each of the groups ofpassages 322 within the stator 312. Accordingly, for example, syringebarrel 325-1 is associated with the passages of group 322-1, etc. Inoperation, rotation of the rotor 311 to position 1, causes the syringebarrels to align with each of the passages 320-x,1. This position cancorrespond to a measurement cycle, for example, with passage 320-1,1connected with a source of sample, passage 320-2,1 connected with asource of reagent, and passage 320-3,1 connected with a source of acid.Likewise, the passages 320-x,3 along position 3 can correspond with areagent blank cycle as described above.

Referring back to the lab on a valve system 100 of FIG. 1, someembodiments further comprise a mixer 120. The mixer 120 can be coupledwith the sample preparation assembly 110 via mixer line outlets 118. Forexample, in the embodiment of FIG. 2A, the mixer line outlets comprisethe outlet connectors 221. The outlet connectors 221 provide forsimultaneous delivery of multiple fluids to the mixer 221. Upon reachingthe mixer 120, the fluids from each of the mixer line inputs are mixed.

The mixer 120 can provide thorough mixing of metered fluid volumesdispensed by the sample preparation assembly 110. In a use compositionmonitor, appropriate mixing can ensure that the response data measuredby the sensor 122 leads to an accurate determination of thecharacteristic of the use composition to be determined. The mixer 120may be implemented using any conventional device designed to rapidly mixtogether two or more fluids. For example, the mixer 120 may be a pieceof tubing with internal baffles that cause flow reversal of the fluidsto result in rapid mixing. The mixer 120 may also be implemented using aknotted reactor, reaction coil, serpentine or other fluid mixing deviceknown in the art. An example baffle-type static mixer is the Series 120Individual Mixing Elements available from TAH Industries Inc,Robbinsville, N.J. However, it shall be understood that any suitablemixer may be used without departing from the scope of the presentinvention, and that the invention is not limited in this respect.

Mixed or otherwise dispensed fluid can then be delivered to a sensor122. The sensor measures at least one characteristic of the fluidmixture indicative of the properties to be determined. The measurementsobtained by sensor 122 are referred to herein as “response data.” Forexample, properties to be determined can be the concentrations ofperacid and/or hydrogen peroxide in a use composition. Controller 126determines the properties based on the response data. In someembodiments, the sensor 122 is an optical detector that measures thetransmittance and/or the absorbance of the fluid mixture. In suchembodiments, the response data may be the optical transmittance data oroptical absorbance data of the sample as a function of time. In otherembodiments, the sensor 122 may measure other characteristics indicativeof the particular property to be determined, such as fluorescence, pH,oxidation-reduction potential, conductivity, mass spectra and/orcombinations thereof. In such embodiments, the response data would bethe corresponding measured characteristic at the appropriate points intime. Example sensors 122 include photometric, pH, ORP, conductivity orother sensors. The photometric sensors utilized can operate in thevisible, ultraviolet or infrared wavelength range, although otherluminescence detection techniques may also be used without departingfrom the scope of the present invention. One example of a suitablecommercially available photometric detector can be assembled using aDT-MINI-2 Deuterium Tungsten Source, FIA-Z-SMA-PEEK Flow Cell andUSB4000 Miniature Fiber Optic Spectrometer, all available from OceanOptics Inc., Dunedin, Fla. It shall be understood, however, that anysuitable optical detector may be used without departing from the scopeof the present invention, and that the invention is not limited in thisrespect. Indeed, an appropriate optical sensor may be any of thosedescribed for use with respect to U.S. patent application Ser. No.12/370,369, which is presently co-owned and is herein incorporated byreference.

In the case of an optical sensor, the voltage response of the sensorcorresponds to the amount of the light transmitted through the samplemixture. Sensor 122 thus essentially measures the change of the samplesolution optical properties within the sensor 122 as a function of time.The transmittance is the ratio of the intensity of light coming out ofthe sample (I) to intensity of light incident to the sample (I₀),T=I/I₀. Once the transmittance of the sample is measured, the absorbance(A) of the sample may be calculated. The absorbance or optical density(A) is a logarithmic function of the transmittance;A=−log₁₀T=−log₁₀I/I₀=log₁₀I₀/I. With respect to embodiments used todetermine the concentrations of peracid and peroxide within a usecomposition, as is discussed above, the initial absorbance of the sample(A₀) is indicative of the concentration of peracid in the usecomposition and the sample absorbance variation over time is indicativeof the concentration of hydrogen peroxide in the use composition.However, as is further indicated, this relationship may not hold trueacross wide ranging use composition concentrations. For example, athigher concentrations, e.g. above 500 ppm peracid, concentration ofperacid is a function of both initial absorbance and, to a lesserdegree, absorbance over time. Accordingly, to provide instrumentscapable of accommodating use with a wide concentration range, i.e. arange encompassing both concentration ranges described above,alternative methods must be utilized.

Additionally, the wavelength tested by the optical sensor can beselected based upon the particular application of the lab on a valveanalytical system. Indeed, some embodiments include sensorsincorporating emitters of multiple wavelengths. With respect toperacid/peroxide concentration determination, wavelength selection isbased on the spectral response of the triiodide complex, and may bewithin the range of 350 to 450 nanometers, for example. A two wavelengthsystem may utilize the wavelengths 375 nanometers and 405 nanometers,for example.

Some embodiments of lab on a valve analytical systems are optimized foruse as an on site use composition monitor. That is, there is a need foraccurate and reliable sensors to measure use composition properties,e.g. peracid and peroxide concentrations, when ambient temperature canvary in wide range. Unstable temperature inside of a system has beenfound to contribute to random variations in concentration readings.Potential causes of such temperature instability include environmentaltemperature variances and locally generated heat and air flow fromcomponents of the measurement system such as pumps, step motors, andelectronic components, such as, the controller. Thus, some embodimentsinclude additional features to adjust the temperature of the fluidmixture within the sensor or prior to reaching the sensor. In addition,systems according to some embodiments provide means for adjusting orstabilizing the temperature of sample prior to delivery to the detectorto avoid the inconsistencies associated with in field operation. Suchsystems may include those described in commonly owned U.S. patentapplication Ser. No. 12/370,369, which has been incorporated byreference herein.

An advantage of lab on a valve systems according to embodiments of thepresent invention is that they can be set up to automate multiplemeasurement sequences. For example, the lab on a valve analytical system200 of FIG. 2A can be set up to carry out two distinct measurementsequences. For example, one sequence, “the sample measurement sequence,”can be utilized to measure the concentration of peracid/peroxide withina use composition. The second sequence, “the reagent blank sequence,”can be utilized to calibrate the system such that response datacollected during the measurement sequence corresponds only to the usecomposition. The two measurement sequences will be described below.

In the sample measurement sequence use composition, reagent, and acidare connected to a common inlet connector of each of the groups 222 ofthe sample preparation assembly 210. For example, each of thesecomponents can be connected with the first inlet connector 220-x,1 ofeach group 222. In particular, inlet connector 220-1,1 can be connectedwith a source of the use composition, inlet connector 220-2,1 can beconnected with a source of reagent, and inlet connector 220-3,1 can beconnected with a source of acid. Inlet connector 220-4,1 may be coupledwith a source of diluent, or alternatively in some embodiments, it maynot be used. If one inlet or outlet connector in a group is not usedthen all connectors of this group should be not used and not pluggedbecause the plugged connector will restrict movement of the plungerassociated with this group of connectors. As described above, withrespect to the determination of concentration of peracid/peroxide withina use composition, the reagent can comprise potassium iodide, and theacid can comprise acetic acid.

Continuing with the sample measurement sequence, the sample preparationassembly 210 can manage the simultaneous delivery of volumes of thecomponents. This can be accomplished as described above. In the samplemeasurement sequence, the result is that metered volumes of usecomposition, reagent, and acid are delivered via the outlet connections221. These fluids are directed to the mixer 120 which thoroughly mixesthe fluids and provides a sample mixture. The sample mixture isdelivered to the sensor 122, where response data is collected. Followingthe collection of response data, the sample mixture can be disposed ofalong waste line 124. A controller 126, can then process the responsedata to determine the concentrations of peracid and/or peroxide withinthe use composition.

The reagent blank sequence manages the preparation and testing of a“reagent blank” to determine calibration data that can be used incalculating the final output, e.g. peracid/peroxide concentration,during the measurement sequence. The reagent blank comprises a volume ofmixed fluids equal in volume to that which will be tested during themeasurement sequence, but with a fluid having a known absorbancereplacing the use composition. For example, the reagent blank cancomprise water, reagent, and acid, the water having a known absorbance.

For the reagent blank sequence, water, reagent, and acid can beconnected to a common inlet connector of each of the groups 222 of thesample preparation assembly 210. For example, each of these componentscan be connected with the third inlet connector 220-x,3 of each group.In particular, inlet connector 220-1,3 can be connected with a source ofwater, inlet connector 220-2,3 can be connected with a source ofreagent, and inlet connector 220-3,3 can be connected with a source ofacid. Inlet connector 220-4,3 may be coupled with a source of diluent,or alternatively in some embodiments, it may not be used.

Continuing with the reagent blank sequence, the sample preparationassembly 210 can manage the simultaneous delivery of volumes of thecomponents as described above. However, here, rather than rotating toposition 1, the rotor is rotated to position 3, to provide connectionwith the components of the reagent blank. The result is that meteredvolumes of water, reagent, and acid are delivered via the outletconnections 221. These fluids are directed to the mixer 120 whichthoroughly mixes the fluids and provides the reagent blank. The reagentblank is delivered to the sensor 122, where response data is collected.Following the collection of response data, the reagent blank can bedisposed of through a connected waste line 124. A controller 126, canthen process the response data to determine offsets or other calibrationvalues to be utilized in the measurement sequence calculations. Theseoffsets may be due to contributions to absorbance of the reagent or aciditself, or other environmental considerations. Thus, embodimentsaccording to the present invention can manage the preparation andanalysis of multiple samples, i.e. a measurement sample and a reagentblank sample. One of ordinary skill in the art will recognize that othersample preparations (e.g. samples utilizing additional sample sources,different reagents, etc.) may be substituted for, or added in additionto the reagent blank sequence described above.

Some embodiments comprise a measurement unit that combines all essentialcomponents for sample preparation and measurement in one analyzer unit.Such a unit can be used to manage all steps of the analytical operation,from sample preparation to measurement calculation and output. In someembodiments, the measurement unit can be a portable measurement unit.

For example, FIGS. 4A and 4B show front and rear views, respectively, ofa portable analyzer 400 according to some embodiments. The portableanalyzer 400 includes a splash-proof housing 405, which houses theanalytical device components. The splash-proof housing 405 has a lid 406with a handle 407 secured by locks 408. The front wall of the analyzer400 includes a display 409, keypad 410, and battery compartment cover411. According to some embodiments, the analyzer 400 is powered by a 9 Vpower source. Such power can be supplied by battery (e.g. nine AAbatteries) or from a 9V DC power supply via a DC power connector 412. Inaddition, the analyzer 400 can include a USB or other connection port413 which can provide for connection to a computer or monitoring systemvia USB or other appropriate cable.

Additionally, the analyzer 400 includes one or more connections to asample source. The sample source connection can comprise an input port414 having a polyfluorocarbon input tube 415 (for example 0.50 mm ID, 10cm length PTFE tubing TTF-120 from VICI Valco Instruments Co. Inc.,Houston, Tex.). The input tube 415 can be used during calibration, orfor analyzing a discrete sample 416. For continuous monitoring, asampling flow cell 417 can be connected directly to the sample inputport 414. By this arrangement, use composition continuously flows froman input tube 418 into an output tubing 419 of the sampling flow cell417, providing fresh solution for analysis.

FIG. 4B shows a rear plan view of the analyzer 400 of FIG. 4A. At therear, the analyzer 400 can include an input access cover 420 and a wasteaccess cover 421.

FIG. 4C shows a cross-section of the analyzer 400 along the plane C-C.With the locks 408 open, the lid 406 can be removed to provide access toreplaceable solution reservoirs located within the housing 405. Inaddition, the input access cover 420 can be removed to provide easyaccess to such reservoirs. The replaceable solution reservoirs providesources of solutions, or components utilized during the wet chemicalanalytical procedures performed by the device. For example, with respectto a peracid/peroxide analyzer, the solution reservoirs can comprise aKI reservoir 422, an acid reservoir 423, and a water reservoir (notvisible in this view). In some embodiments, the replaceable solutionreservoirs can comprise metalized plastic bags having a puncturableinterface. The puncturable interface of each bag can be directlyconnected to a corresponding needle port of the lab on a valve assembly500 which is contained within the analyzer 400. Each of the bags hasvolume approximately 200 ml which stays in degassed condition duringoperation. Solution bags of this volume can provide for approximately3000 analysis sequences, at which time, the reservoirs should bereplaced or refilled. Each of the needle port connections can haveinternal volumes less than 10 μl and create a sealed connection to thewater and reagents providing for extended reagent lifetime, e.g. atleast 6 months.

Needle ports 425, 426 (and others if necessary) provide for inputconnection from solution reservoirs to the lab on a valve assembly.Sample input connection can be provided by a short polyfluorocarbontubing 428 (for example 0.50 mm ID, 10 cm length PTFE tubing TTF-120from VICI Valco Instruments Co. Inc., Houston, Tex.) connected frominput port 414 to the lab on a valve assembly 500. Additionally, wastetubing 429 can provide fluid output from the lab on a valve assembly500. The waste tubing 429 can extend through optical cell 430 andinclude a needle connector 431 at its end, allowing for a sealedconnection to a waste bag 432 through a puncturable interface. The wastebag 432 can have a volume of approximately 800 ml. During use, the wastebag can be emptied or replaced when new water and reagent bag reservoirsare installed in the analyzer 400. The waste bag 432 can be replaced byremoving access cover 421 in the housing 405 of the analyzer 400.Alternatively, the waste tubing 429 can connect with an external outputconnector which can allow waste solution to continuously flow out of thehousing 405.

The analyzer 400 further includes an electronics board 433 whichcontains all electronic device controls, electronic drivers, and powersupplies. The electronics board 433 can be secured vertically within thehousing 405, adjacent the internal surface of the front panel to allowaccess to the electronic components mounted therein. The electronicsboard 433 can include, for example, a controller, memory, and real timeclock, for carrying out the various measurement sequences associatedwith the analyzer 400 and performing the calculations necessary todetermine the desired unknown. For example, the controller can be usedto determine the concentrations of peracid and peroxide within a usecomposition based upon response data collected from an optical sensor.Accordingly, the electronics board 433 can include various sensor andcontrol connectors. For example, the electronics board 433 can include alight emitting diode in a mount 435 in optical communication with afirst optical fiber 436, and a photodiode in a mount 437 in opticalcommunication with a second optical fiber 438. The first optical fiber436 can be used to deliver light to the optical cell and the secondoptical fiber 438 can collect the delivered light after it has passedthrough a volume of the sample. Readings from the photodiode 437 canthus comprise the response data. In addition, the electronics board 433can comprise other components for calibrating or monitoring the opticalcell such as, for example, a connection 434 to a temperature sensorlocated at the optical cell. The control outputs of the electronicsboard 433 can include an electrical driver 440 for controlling athermo-electrical cooler coupled with the optical cell. This electricaldriver 440 can comprise a single input driver which is based off ofinput from the temperature sensor 434, such as the temperature controlcircuit described in commonly owned U.S. patent application Ser. No.12/370,362, entitled “H-Bridge Control Circuit,” which is herebyincorporated by reference. Moreover, the electronics board 433 caninclude first and second electrical drivers 441, 442 for controlling theelectrical step motors used to control the lab on a valve assembly 500.

Additionally, the electronics board 433 can include I/O connectors. Forexample, the electronics board 433 can include a connection foroutputting data to the display 409, a connection for communicating withthe keypad 410, and/or a connection for communicating with the USB orother connection port 413. In some embodiments, power supply componentscan be integrated with the electronics board 433. For example, theelectronics board can include connection to an external power supplyand/or holders for batteries 439.

The lab on a valve assembly 500 of the portable analyzer 400 is shown ingreater detail in FIGS. 5A and 5B. FIG. 5A shows a cross-sectional viewof the lab on a valve assembly 500 as indicated by region 5A of FIG. 4C.FIG. 5B shows a cross-sectional view of the lab on a valve assembly 500along the plane B-B of FIG. 5A. FIGS. 6A-6C show an exploded view of thelab on a valve assembly 500. FIG. 7A shows a transparent, perspectiveview of the disks which comprise the lab on a valve assembly.Additionally, FIGS. 7B-7D show top and bottom views of the three disks101, 102, 103 shown in FIG. 7A. FIG. 7B shows top and bottom views ofthe interface disk 103. FIG. 7C shows top and bottom views of the valvedisk 102. FIG. 7D shows top and bottom views of the rotor disk 101.While it includes an additional layer not disclosed in the lab on avalve assemblies described above, the principles and general operationassociated with the particular embodiment of the lab on a valve assemblydisclosed in FIGS. 5A-7D is commensurate with the embodiments describedabove with respect to FIGS. 2A-3B. Accordingly, the variations andfeatures of the lab on a valve assemblies described above can beincorporated into the embodiments shown in FIGS. 5A-7D. In addition,nothing disclosed herein is intended to limit the use of a particularlab on a valve assembly with the analyzer 400 or other devices disclosedherein.

The lab on a valve assembly 500 of FIGS. 5A-7D comprises three stackeddisks 501, 502, 503 which can be seen in FIG. 5A. The rotor disk 501comprises internal micro pumps 510 and can be rotated around thevertical axis to be set in several discrete positions relative to thevalve disk 502. The valve disk 502 is fused or clamped to an interfacedisk 503 which includes connection ports for receiving sample inputtubing 528, reagent bags (via needle connectors 425, 426, 427), and thesensor assembly. In some embodiments, the interface disk 503 furtherincludes an integral mixer 511 (this integral mixer can take the placeof an external mixer as shown in FIG. 1). The interface disk 503 and thevalve disk 502 can be secured within a valve cover 555 by screws 556.These screws 556 can engage the disks 503, 502 via threaded holes 733within one or more of the disks. Compression between the two disks,turns channels formed in a surface of the interface disk 503 intointernal passages for directing fluid flow within the assembly 500. Oneexample of channels within the interface disk 503 can be seen in thebottom view of FIG. 7B. In the device shown here, three channels 711,712, 713 connect a mixer 715 with output passages from various passagegroups. Additional channels have been included to provide connectionsbetween the various input passages, e.g. sample channel 721, waterchannel 722, acid channel 723, and reagent channel 724.

The rotor disk 501 can be connected with the stator disks (in thisembodiment: the valve disk 502 and interface disk 503) in the valvecover 555 by a bolt 557 with a spring washer 558 inserted from thebottom of the disk 501 and a nut 559 placed on the top of the valvecover 555. The connection between these elements is such that the rotordisk is capable of being rotated about the vertical axis whilemaintaining a fluid seal between the elements. Accordingly, as with thesample preparation assemblies described above, openings 730 in the rotordisk face can be selectively aligned with channels within the valve disk502, and thus passages within the interface disk 503. For example, inposition 1 the channels can enable water, reagent, and acid to be drawninto the syringe pumps 510 in order to prepare a reagent blank. Fromposition 2 the contents of the syringes, whether a reagent blank orsample solution, can be injected into the mixer. In position 3 thechannels enable the sample, KI and acid to be drawn into the syringes inorder to prepare a sample solution.

With reference to FIGS. 5A, 5B, 6B, and 6C, the syringe pumps 510 areeach formed out of a generally cylindrical cavity formed within therotor disk 501, and a plunger 570 inserted therein. The stems of theplungers 570 can be threaded and include a through-hole into which aguiding pin can be inserted. The guiding pin can prevent the rotation ofthe plunger as it moves up and down the cylindrical cavity. Each plungercavity can accordingly include two guide groves to receive the guidingpin and allow it to ascend and descend. The vertical displacement of thethreaded plunger 570 of each syringe pump can be controlled by rotatingdrive gears 572 having a central nut that receives the threaded end ofthe plunger 570. As the drive gears 572 rotate, the guiding pins 571prevent the plungers from rotating along with them. The drive gears 572can be press fit into ball bearing receivers 573, and each ball bearingreceiver 573 can be secured in the corresponding cylindrical cavity ofthe rotor disk by a set screw inserted from the edge of the disk. Eachof the syringe drive gears 572 can be driven by the rotation of acentral gear 574 which is secured by another set screw to the axis of afirst motor 575. For simplicity of calculation of rotation (whichcorrelates with dispensed pump volume) a step motor can be used.Alternative embodiments can include the use of a DC motor which requiresthe addition of opto-couples for synchronization and counting therotations of the motor. The step motor 575 can be secured to housing 576with screws 577. The housing 576 is attached to the cylindrical surfaceof the rotor disk 501 and protects the step motor 575, drive gears 572,574, and syringe assemblies.

The rotation of the rotor disk 501 relative to the stator disks 502, 503can be enabled by a second motor 580 secured to the side of the cover555. A gear 581 connected to the axel of the second motor 580 by anotherset screw, interlocks with the large gear teeth (visible, for example,in FIGS. 6B and 7D) on the outside of the rotor disk 501. This allowsfor alignment of the micropumps 510 within the rotor disk 501 with thevarious connections provided by the valve disk 502. In some embodiments,due to the requirement of only a limited angle of rotation of the rotor(e.g. sufficient rotation of θ_(A) plus θ_(B) degrees in the embodimentshown in FIG. 2C) in some embodiments, only a small portion of theoutside of the rotor disk 501 needs to be geared.

Referring now primarily to FIGS. 5A-6B, the cover 555 has severalopenings corresponding with ports on the top surface of the interfacedisk 503. These ports can comprise needle ports for connecting solutionbags as described above. For example, in a peracid monitor, the portscan include three needle ports 425, 426, 427. Each needle port cancomprise a needle 425, 426, 427 secured by a nut 553. In such anexample, these needle ports can be associated with connection to asource of reagent (e.g. KI) 423, a source of acid 422, and a source ofwater 424, such as the metalized bags previously discussed. In addition,the connection ports can comprise tubing connected with the samplepreparation assembly. For example, sample tubing 428 can be connected tothe interface layer 503 water-tightly with a nut 554 and a gasket 550.

With continued reference to FIGS. 5A-7B, in some embodiments, theoptical cell can be connected directly to the interface layer. Inparticular, embodiments which include an integral mixer 511 such as thatshown here can couple the optical cell or other sensor directly to theoutput of the integral mixer. The optical cell assembly can comprise apolyfluorocarbon tube 429 passing through a copper body 548. The sensorline 429 can be connected with the mixer outlet of the interface disk503 with a gasket 550. A plastic thermal-insulating insert 549 can beused to separate the copper body 548 from cover 555. The copper body 548includes a through-hole generally perpendicular to the main cell channelinto which first and second optical fibers 436, 438 can be inserted. Asdescribed above, the first optical fiber 436 can transmit light from alight source (e.g. LED 435) and the second optical fiber can transmitlight to a detector (e.g. photodiode 437). A temperature sensor 434 canbe inserted into a slot in the top of the copper body 548.Thermo-electric Peltier modules 545 can be placed on the top surface ofthe copper body 548, above the through-hole. The Peltier modules 545 canbe positioned adjacent the copper body 548 within a thermally insulatingcutout 546. Accordingly, via control inputs 552 the Peltier modules 545can be used to apply or remove heat from the copper body 548 (i.e. theoptical cell) based upon feedback data from the temperature sensor 434.A thermal-insulating sleeve 531 can be slid around the whole opticalcell assembly to further thermally isolate the cell. Additionally, aheat sink 560 can be affixed over the Peltier modules 545 secured to thecopper body 548 by plastic screws 547. In certain embodiments of thisdesign a mini fan with a brushless DC motor can be used to improve theefficiency of the Peltier modules 545.

As used herein, the term “peracid” refers to any acid that in which thehydroxyl group (—OH) is replaced with the peroxy group (—OOH). Theperacid(s) may be C2-C18 peracid(s), such as C2 (peracetic) acid and C8(peroctanoic) acid. It shall be understood that the apparatus and/ormethods of the present invention may detect the combined presence of allperacids in a sample, whether the sample contains one or more than onedifferent peracids, and that the invention is not limited in thisrespect.

Peroxycarboxylic acids generally have the formula R(CO₃H)_(n). In someembodiments, the R may be an alkyl, arylalkyl, cycloalkyl, aromatic orheterocyclic group, and n may be one or two.

Peroxycarboxylic acids useful in this invention include peroxyformic,peroxyacetic, peroxypropionic, peroxybutanoic, peroxypentanoic,peroxyhexanoic, peroxyheptanoic, peroxyoctanoic, peroxynonanoic,peroxydecanoic, peroxylactic, peroxymaleic, peroxyascorbic,peroxyhydroxyacetic, peroxyoxalic, peroxymalonic, peroxysuccinic,peroxyglutaric, peroxyadipic, peroxypimelic and peroxysubric acid andmixtures thereof as well others known to those of skill in the art.

The concentrations of peracid and/or peroxide determined by usecomposition monitor may be used, for example, as feedback to controllerto maintain the peracid concentration in the use composition within apredefined range and/or to cause the emptying of the use compositionvessel and production of a new use composition when the hydrogenperoxide concentration exceeds the maximum peroxide thresholdconcentration. If, for example, the concentration of peracid in the usecomposition decreases below a predetermined level, the use compositionmay be replenished by adding a concentrated peracid composition to theuse composition. As another example, if the concentration of peroxide inthe use composition exceeds a predetermined level, the use compositionmay be replenished by emptying the use composition vessel of the spentuse composition and generating a new use composition.

Use compositions including peracids and peroxides described herein maybe used for a variety of domestic or industrial applications, e.g., toreduce microbial or viral populations on a surface or object or in abody or stream of water. The compositions may be applied in a variety ofareas including kitchens, bathrooms, factories, hospitals, dentaloffices and food plants, and may be applied to a variety of hard or softsurfaces having smooth, irregular or porous topography. Suitable hardsurfaces include, for example, architectural surfaces (e.g., floors,walls, windows, sinks, tables, counters and signs); eating utensils;hard-surface medical or surgical instruments and devices; andhard-surface packaging. Such hard surfaces may be made from a variety ofmaterials including, for example, ceramic, metal, glass, wood or hardplastic. Suitable soft surfaces include, for example paper; filtermedia, hospital and surgical linens and garments; soft-surface medicalor surgical instruments and devices; and soft-surface packaging. Suchsoft surfaces may be made from a variety of materials including, forexample, paper, fiber, woven or nonwoven fabric, soft plastics andelastomers. The compositions may also be applied to soft surfaces suchas food and skin (e.g., a hand). The use compositions may be employed asa foaming or nonfoaming environmental sanitizer or disinfectant.

The compositions may be included in products such as sterilants,sanitizers, disinfectants, preservatives, deodorizers, antiseptics,fungicides, germicides, sporicides, virucides, detergents, bleaches,hard surface cleaners, hand soaps, waterless hand sanitizers, and pre-or post-surgical scrubs.

The compositions may also be used in veterinary products such asmammalian skin treatments or in products for sanitizing or disinfectinganimal enclosures, pens, watering stations, and veterinary treatmentareas such as inspection tables and operation rooms. The compositionsmay be employed in an antimicrobial foot bath for livestock or people.

The compositions may be employed for reducing the population ofpathogenic microorganisms, such as pathogens of humans, animals, and thelike. The compositions may exhibit activity against pathogens includingfungi, molds, bacteria, spores, and viruses, for example, S. aureus, E.coli, Streptococci, Legionella, Pseudomonas aeruginosa, mycobacteria,tuberculosis, phages, or the like. Such pathogens may cause a varietiesof diseases and disorders, including Mastitis or other mammalian milkingdiseases, tuberculosis, and the like. The compositions may reduce thepopulation of microorganisms on skin or other external or mucosalsurfaces of an animal. In addition, the compositions may kill pathogenicmicroorganisms that spread through transfer by water, air, or a surfacesubstrate. The composition need only be applied to the skin, otherexternal or mucosal surfaces of an animal water, air, or surface.

The compositions may also be used on foods and plant species to reducesurface microbial populations; used at manufacturing or processing siteshandling such foods and plant species; or used to treat process watersaround such sites. For example, the compositions may be used on foodtransport lines (e.g., as belt sprays); boot and hand-wash dip-pans;food storage facilities; anti-spoilage air circulation systems;refrigeration and cooler equipment; beverage chillers and warmers,blanchers, cutting boards, third sink areas, and meat chillers orscalding devices. The compositions may be used to treat producetransport waters such as those found in flumes, pipe transports,cutters, slicers, blanchers, retort systems, washers, and the like.Particular foodstuffs that may be treated with compositions includeeggs, meats, seeds, leaves, fruits and vegetables. Particular plantsurfaces include both harvested and growing leaves, roots, seeds, skinsor shells, stems, stalks, tubers, corms, fruit, and the like. Thecompositions may also be used to treat animal carcasses to reduce bothpathogenic and non-pathogenic microbial levels.

The composition may be useful in the cleaning or sanitizing ofcontainers, processing facilities, or equipment in the food service orfood processing industries. The compositions may be used on foodpackaging materials and equipment, including for cold or hot asepticpackaging. Examples of process facilities in which the compositions maybe employed include a milk line dairy, a continuous brewing system, foodprocessing lines such as pumpable food systems and beverage lines, etc.Food service wares may be disinfected with the compositions. Forexample, the compositions may also be used on or in ware wash machines,dishware, bottle washers, bottle chillers, warmers, third sink washers,cutting areas (e.g., water knives, slicers, cutters and saws) and eggwashers. Particular treatable surfaces include packaging such ascartons, bottles, films and resins; dish ware such as glasses, plates,utensils, pots and pans; ware wash machines; exposed food preparationarea surfaces such as sinks, counters, tables, floors and walls;processing equipment such as tanks, vats, lines, pumps and hoses (e.g.,dairy processing equipment for processing milk, cheese, ice cream andother dairy products); and transportation vehicles. Containers includeglass bottles, PVC or polyolefin film sacks, cans, polyester, PEN or PETbottles of various volumes (100 ml to 2 liter, etc.), one gallon milkcontainers, paper board juice or milk containers, etc.

The compositions may also be used on or in other industrial equipmentand in other industrial process streams such as heaters, cooling towers,boilers, retort waters, rinse waters, aseptic packaging wash waters, andthe like. The compositions may be used to treat microbes and odors inrecreational waters such as in pools, spas, recreational flumes andwater slides, fountains, and the like.

A filter containing a composition may reduce the population ofmicroorganisms in air and liquids. Such a filter may remove water andair-born pathogens such as Legionella.

The compositions may be employed for reducing the population ofmicrobes, fruit flies, or other insect larva on a drain or othersurface.

The compositions may also be employed by dipping food processingequipment into the use solution, soaking the equipment for a timesufficient to sanitize the equipment, and wiping or draining excesssolution off the equipment. The compositions may be further employed byspraying or wiping food processing surfaces with the use solution,keeping the surfaces wet for a time sufficient to sanitize the surfaces,and removing excess solution by wiping, draining vertically, vacuuming,etc.

The compositions may also be used in a method of sanitizing hardsurfaces such as institutional type equipment, utensils, dishes, healthcare equipment or tools, and other hard surfaces. The composition mayalso be employed in sanitizing clothing items or fabrics which havebecome contaminated. The composition is contacted with any contaminatedsurfaces or items at use temperatures in the range of about 4° C. to 60°C., for a period of time effective to sanitize, disinfect, or sterilizethe surface or item. For example, the composition may be injected intothe wash or rinse water of a laundry machine and contacted withcontaminated fabric for a time sufficient to sanitize the fabric. Excesscomposition may be removed by rinsing or centrifuging the fabric.

The compositions may be applied to microbes or to soiled or cleanedsurfaces using a variety of methods. These methods may operate on anobject, surface, in a body or stream of water or a gas, or the like, bycontacting the object, surface, body, or stream with a composition.Contacting may include any of numerous methods for applying acomposition, such as spraying the composition, immersing the object inthe composition, foam or gel treating the object with the composition,or a combination thereof.

The composition may be employed for bleaching pulp. The compositions maybe employed for waste treatment. Such a composition may include addedbleaching agent.

Other hard surface cleaning applications for the compositions includeclean-in-place systems (CIP), clean-out-of-place systems (COP),washer-decontaminators, sterilizers, textile laundry machines, ultra andnano-filtration systems and indoor air filters. COP systems may includereadily accessible systems including wash tanks, soaking vessels, mopbuckets, holding tanks, scrub sinks, vehicle parts washers,non-continuous batch washers and systems, and the like.

Thus, embodiments of the valve analytical system are disclosed. Althoughthe present invention has been described in considerable detail withreference to certain disclosed embodiments, the disclosed embodimentsare presented for purposes of illustration and not limitation and otherembodiments of the invention are possible. One skilled in the art willappreciate that various changes, adaptations, and modifications may bemade without departing from the spirit of the invention and the scope ofthe appended claims.

1. A method for analyzing one or more characteristics of a usecomposition, the method comprising: providing a rotary valve analyticalsystem comprising: a rotor having a rotor face, the rotor beingrotatable about an axis perpendicular to the rotor face, wherein therotor face has a plurality of openings, each of which extends into therotor to form syringe barrels; a stator disposed coaxially with therotor, the stator having a stator face in sealable, slidable, rotarycontact with the rotor face, wherein the stator comprises a plurality ofinlet passages and outlet passages passing therethrough, each inletpassage providing for fluid communication between a fluid source and anopening within the stator face, and each outlet passage providing forfluid communication between an opening within the stator face and amixer line, wherein one or more of the fluid sources comprises a sourceof the use composition; a mixer having a plurality of inputs each influid communication with one of the mixer lines and an output in fluidcommunication with a sensor line; and a sensor coupled with the sensorline; rotating the rotor to a first position, such that the syringebarrels within the rotor are aligned with one or more of the inletpassages within the stator and the other openings within the stator faceare sealed by the rotor face, wherein one or more of the aligned inletpassages are in fluid communication with the source of the usecomposition; drawing fluid into each of the syringe barrels from thealigned inlet passages; rotating the rotor to a second position, suchthat each of the syringe barrels are aligned with one of the outletpassages and the other openings within the stator face are sealed by therotor face; driving fluid from the syringe barrels and through thealigned fluid outlet passages into the mixer lines; mixing the fluids inthe mixer resulting in a sample mixture within the sensor line;measuring one or more properties of the sample mixture with the sensor,the properties being indicative of the one or more characteristics ofthe use composition; and determining the one or more characteristics ofthe use composition from the measurement.
 2. The method of claim 1,further comprising disposing of the sample mixture after measuring oneor more properties of the sample mixture.
 3. The method of claim 1,wherein drawing fluid into each of the syringe barrels comprises drawingthe use composition into a first syringe barrel, drawing a reagent intoa second syringe barrel, and drawing an acid into a third syringebarrel.
 4. The method of claim 3, wherein drawing fluid into each of thesyringe barrels further comprises drawing a diluent into a fourthsyringe barrel.
 5. The method of claim 3, wherein the reagent comprisespotassium iodide, and the acid comprises acetic acid.
 6. The method ofclaim 1, further comprising performing a calibration cycle, thecalibration cycle comprising: rotating the rotor to a third position,such that the syringe barrels within the rotor are aligned with one ormore of the inlet passages within the stator and the other openingswithin the stator face are sealed by the rotor face, wherein none of thealigned inlet passages are in fluid communication with the source of theuse composition; drawing fluid into each of the syringe barrels from thealigned inlet passages; rotating the rotor to the second position, suchthat each of the syringe barrels are aligned with one of the outletpassages and the other openings within the stator face are sealed by therotor face; driving fluid from the syringe barrels and through thealigned fluid outlet passages into the mixer lines; mixing the fluids inthe mixer to produce a blank mixture within the sensor line; measuringone or more calibration properties of the blank mixture with the sensor;and storing the calibration properties such that the calibrationproperties can be used during the determination of the one or morecharacteristics of the use composition.
 7. The method of claim 6,wherein drawing fluid into each of the syringe barrels during thecalibration cycle comprises drawing water into a first syringe barrel,drawing a reagent into a second syringe barrel, and drawing an acid intoa third syringe barrel.
 8. The method of claim 1, wherein the sensorcomprises an optical sensor, and the one or more properties of thesample mixture comprise one or more optical properties thereof.
 9. Themethod of claim 8, wherein the one or more optical properties compriseat least one of transmittance, absorbance, fluorescence, and a time or atemperature derivative thereof.
 10. The method of claim 8, wherein theone or more optical properties comprise absorbance and a time derivativeof absorbance.
 11. The method of claim 1, wherein the one or morecharacteristics of the use composition comprises the concentration ofone or more analytes within the use composition.
 12. The method of claim11, wherein the one or more analytes comprise a peracid and a peroxide.13. The method of claim 1, wherein from 10 μl to 100 μl of fluid aredrawn into and driven from the syringe barrels.
 14. The method of claim13, wherein 30 μl of fluid are drawn into and driven from the syringebarrels.
 15. The method of claim 1, wherein rotating the rotor to thefirst position and rotating the rotor to the second position eachcomprise actuating a rotor drive motor to rotate the rotor.
 16. Themethod of claim 1, wherein rotating the rotor to the second positioncomprises rotating the rotor while fluid drawn into each of the syringebarrels is held in each of the syringe barrels.
 17. The method of claim1, wherein the rotor defines a rotor face, and the stator defines astator face, and rotating the rotor to the first position and rotatingthe rotor to the second position each comprise sliding the rotor faceover the stator face while maintaining a fluid seal such that fluidcannot seep between the rotor face and the stator face.
 18. A lab on avalve analytical system for determining a concentration of a peracid anda peroxide within a use composition, comprising: a valve assembly,comprising: a rotor having a rotor face and a plurality of syringebarrels extending into the rotor from openings in the rotor face, therotor being rotatable about an axis perpendicular to the rotor face, astator disposed coaxially with the rotor, the stator having a statorface in sealable, slidable, rotary contact with the rotor face and aplurality of groups of passages, each group of passages comprising aplurality of passages each of which extends through the stator from anopening on the stator face to a connector port, wherein each passage ofthe groups of passages is disposed at a common radial distance from theaxis such that each group of passages can be aligned with at least onesyringe barrel by rotating the rotor relative to the stator, and aplurality of syringe plungers, one of said syringe plungers disposed ineach of the syringe barrels, each syringe plunger adapted to draw fluidinto and drive fluid from the syringe barrel in which it is disposed,wherein one or more of the connector ports is in fluid communicationwith a source of the use composition, one or more of the connector portsis in fluid communication with a source of a reagent, and one or more ofthe connector ports is in fluid communication with a source of an acid;a mixer, in fluid communication with the connector port of one of thepassages of each group of passages of the stator, the mixer adapted toproduce a sample mixture comprising quantities of the use composition,the reagent, and the acid; and a sensor in fluid communication with themixer, the sensor adapted to measure one or more properties of thesample mixture indicative of the concentration of the peracid and theconcentration of the peroxide within the use composition.
 19. The lab ona valve analytical system of claim 18, wherein the reagent comprisespotassium iodide.
 20. The lab on a valve analytical system of claim 18,wherein the acid comprises acetic acid.